EP0133236A2 - Thermoplastic moulding compounds - Google Patents

Abstract

The present invention relates to thermoplastic molding compositions composed of (A) thermoplastic polycarbonates, in admixture with (B) thermoplastic polyalkylene terephthalates and optionally with (C) rubber-elastic polymers, which are characterized in that they contain (D) a thermoplastic based on polyetherimide.

Description

• (A) 95 bis 50 Gew.-Teile thermoplastische, aromatische Polycarbonate mit Gewichtsmittelmolekulargewichten M _w zwischen 10 000 und 200 000 (M _w ermittelt mittels Lichtstreuung),
• (B) 50 bis 5 Gew.-Teile thermoplastische Polyalkylentere_- phthalate und gegebenenfalls
• (C) 0 bis 30, vorzugsweise 1 bis 20, insbesondere 3 bis 15 Gew.-Teile eines kautschukelastischen Polymerisats mit einer Glasübergangstemperatur von unter -20°C, wobei die Summe der Gewichtsteile aus (A) + (B) + (C) jeweils 100 Gew.-Teile beträgt, dadurch gekennzeichnet, daß die Polycarbonatkomponente (A) 1 bis 20 Gew.-%, vorzugsweise 1 bis 16 Gew.-% und insbesondere 2 bis 10 Gew.-%, bezogen auf die Summe aus (A) + (D), eines Thermoplasten (D) auf Polyetherimidbasis enthält.

The present invention relates to thermoplastic molding compositions containing

• (A) 95 to 50 parts by weight of thermoplastic, aromatic polycarbonates with weight average molecular weights M _w between 10,000 and 200,000 ( M _w determined by means of light scattering),
• (B) 50 to 5 parts by weight of thermoplastic Polyalkylentere _- phthalate and optionally
• (C) 0 to 30, preferably 1 to 20, in particular 3 to 15 parts by weight of a rubber-elastic polymer having a glass transition temperature of below -20 ° C., the sum of the parts by weight consisting of (A) + (B) + (C) is 100 parts by weight, characterized in that the polycarbonate component (A) 1 to 20 wt .-%, preferably 1 to 16 wt .-% and in particular 2 to 10 wt .-%, based on the sum of (A ) + (D), a thermoplastic (D) based on polyetherimide.

Components (A) to (D) Component (A)

• Hydrochinon,
• Resorcin,
• Dihydroxydiphenyle,
• Bis-(hydroxyphenyl)-C₁-C₈-alkane,
• Bis-(hydroxyphenyl)-C₅-c₆-cycloalkane,
• Bis-(hydroxyphenyl)-sulfide,
• Bis-(hydroxyphenyl)-ether
• Bis-(hydroxyphenyl)-ketone,
• Bis-(hydroxyphenyl)-sulfoxide,
• Bis-(hydroxyphenyl)-sulfone und
• α -α-Bis- (hydroxyphenyl ) -düsopropylbenzole .

Aromatic polycarbonates (A) for the purposes of this invention are the known homopolycarbonates, copolycarbonates and mixtures of these polycarbonates, which are based, for example, on at least one of the following diphenols:

• Hydroquinone,
• Resorcinol,
• Dihydroxydiphenyls,
• Bis (hydroxyphenyl) -C ₁ -C ₈ alkanes,
• Bis- (hydroxyphenyl) -C ₅ -c ₆ -cycloalkanes,
• Bis (hydroxyphenyl) sulfides,
• Bis (hydroxyphenyl) ether
• Bis (hydroxyphenyl) ketones,
• Bis (hydroxyphenyl) sulfoxides,
• Bis (hydroxyphenyl) sulfones and
• α-α-bis (hydroxyphenyl) diisopropylbenzenes.

These and other suitable diphenols are e.g. in U.S. Patents 3,028,365, 3,275,601, 3,148,172, 3,062,781, 2,991,273 and 2,999,846.

Preferred diphenols are, for example, 4,4'-dihydroxydiphenyl, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, Bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfone and bis (4-hydroxyphenyl) ketone.

Particularly preferred diphenols are, for example: 2,2-bis (4-hydroxyphenyl) propane, bis (hydroxyphenyl) methane, bis (4-hydroxyphenyl) sulfone and 1,1-bis (4-hydroxyphenyl) cyclohexane.

The aromatic polycarbonates (A) can, by incorporating small amounts, preferably from 0.05 to 2.0 mol% (based on the diphenols used), of three or more than three-functional compounds, for example those with three or more than three phenolic hydroxyl groups to be branched.

The aromatic polycarbonates (A) are generally intended to have average molecular weights M _{w have} from 10,000 to 200,000, preferably from 20,000 to 80,000, determined by light scattering.

The high molecular weight polycarbonates with M from 10,000 to 200,000 can also contain small proportions of low molecular weight polycarbonates, e.g. with an average degree of polycondensation of 2 to 20.

In order to adjust the molecular weight M of the polycarbonates (A), chain terminators, such as, for example, phenol, halophenols or alkylphenols, are used in the calculated amounts in a known manner.

The polycarbonates (A) to be used according to the invention are prepared in a known manner either by the interfacial process or by the process in homogeneous solution (pyridine process) or, if appropriate, by the melt transesterification process.

Component (B)

Polyalkylene terephthalates (B) in the sense of the invention are reaction products of aromatic dicarboxylic acids or their reactive derivatives (e.g. dimethyl esters) and aliphatic, cycloaliphatic or araliphatic diols and mixtures of these reaction products.

Preferred polyalkylene terephthalates (B) can be prepared from terephthalic acid (or its reactive derivatives, for example dimethyl terephthalate) and aliphatic or cycloaliphatic diols with 2-10 C atoms by known methods (Kunststoff-Handbuch, Vol. VIII, pp. 695 ff, Carl Hanser Verlag, Munich 1973).

Preferred polyalkylene terephthalates (B) contain at least 80, preferably at least 90 mol%, based on the dicarboxylic acid component, terephthalic acid residues and at least 80, preferably at least 90 mol%, based on the diol component, ethylene glycol and / or 1,4-butanediol residues .

In addition to terephthalic acid residues, the preferred polyalkylene terephthalates (B) can contain up to 20 mol% residues of other aromatic or cycloaliphatic dicarboxylic acids Contain 8-14 C atoms or aliphatic dicarboxylic acids with 4-12 C atoms, such as residues of phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, cyclohexanediacetic acid .

The preferred polyalkylene terephthalates (B) in addition ethanediol or butane-1,4-radicals, up to 20 mol% of other aliphatic diols with 3-12 C-atoms or cycloaliphatic diols with 6-21 C-atoms ^- included. e.g. residues of 1,3-propanediol, 2-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethane, 2,4-3-methylpentanediol, 2-2-methylpentanediol , 4, 2,2,4-trimethylpentanediol-1,3 and -1,6, 2-ethylhexanediol-1,3, 2,2-diethylpropanediol-1,3, hexanediol-2,5, 1,4-di- (ß-hydroxyethoxy) benzene, 2,2-bis (4-hydroxycyclohexane) propane, 2,4-dihydroxy-1,1,3,3-tetra-methylcyclobutane, 2,2-bis (3rd -ß-hydroxy-ethoxyphenyl) propane and 2,2-bis (4-hydroxypropoxy-phenyl) propane (DE-OS 24 07 674, 24 07 776, 27 15 932).

The polyalkylene terephthalates (B) can be obtained by incorporating relatively small amounts of trihydric or tetravalent alcohols or 3- or 4-basic carboxylic acids, such as those e.g. are described in DE-OS 19 00 270 and US Pat. No. 3,692,744. Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylol ethane and propane and pentaerythritol.

It is advisable not to use more than 1 mol% of the branching agent, based on the acid component.

Particularly preferred are polyalkylene terephthalates (B) which have been produced solely from terephthalic acid or its reactive derivatives (e.g. its dialkyl esters) and ethylene glycol and / or 1,4-butanediol, and mixtures of these polyalkylene terephthalates.

Preferred polyalkylene terephthalates (B) are also copolyesters which are prepared from at least two of the abovementioned acid components and / or from at least two of the abovementioned alcohol components; particularly preferred copolyesters are poly (ethylene glycol / butanediol-1,4) terephthalates.

The polyalkylene terephthalates preferably used as component (B) generally have an intrinsic viscosity of 0.4 to 1.5 dl / g, preferably 0.5-1.3 dl / g, in particular 0.6-1.2 dl / g, measured in each case in phenol / o-dichlorobenzene (1: 1 part by weight) at 25 ° C.

Component (C)

Rubber-elastic polymers (C) which can be used according to the invention comprise copolymers, in particular graft copolymers, with glass transition temperatures of below -20 ° C., which are essentially obtainable from at least two of the following monomers: chloroprene, butadiene, isoprene, Isobutene, styrene, acrylonitrile, ethylene, propylene, vinyl acetate and (meth) acrylic acid esters with 1-18 C atoms in the alcohol component; thus polymers as described, for example, in "Methods of Organic Chemistry", (Houben-Weyl), Vol. 14/1, Georg Thieme Verlag, Stuttgart 1961, pp. 393-406, and in CB Bucknall, "Toughened Plastics", Appl . Science Publishers, London 1977. Preferred polymers (C) have a gel content of more than 20% by weight, preferably more than 40% by weight.

Preferred polymers (C) are ethylene / vinyl acetate copolymers with 15-45% by weight of vinyl acetate residues and melt indexes from non-flowable to 1000, preferably from 0.1-20, measured at 190 ° C. and a load of 2.16 kg according to DIN 53 735.

Preferred polymers (C) are e.g. the so-called EPM or EPDM rubbers, in which the weight ratio of ethylene and propylene residues is in the range from 40:60 to 65:35.

The Mooney viscosities (ML1 + 4/100 ° C) of the uncrosslinked EPM or EPDM rubbers are between 25-100, preferably between 35-90. The gel contents of the uncrosslinked EPM or EPDM rubbers are below 1% by weight.

The ethylene / propylene copolymers (EPM) used have practically no double bonds, while the ethylene / propylene / diene terpolymers (EPDM) 1-20 May have double bonds / 1000 carbon atoms. Examples of suitable diene monomers in EPDM are: conjugated dienes, for example isoprene and butadiene, and non-conjugated dienes with 5-25 C atoms, for example 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene , 2,5-dimethyl-1,5-hexadiene and 1,4-octadiene; cyclic dienes, for example cyclopentadiene, cyclohexadiene, cyclooctadiene and dicyclopentadiene; Alkenylnorbornenes, e.g. 5-ethyldiene-2-norbornene, 5-butyldiene-2-norbornene, 2-methallyl-5-norbornene, 2-isopropenyl-5-norbornene and tricyclodienes, e.g. 3-methyl-tricyclo- (5.2.1 , 0,2,6) -3,8-decadiene. The non-conjugated dienes hexadiene-1,5, ethylidene-norbornene or dicyclopentadiene are preferred. The diene content in the EPDM is preferably 0.5-10% by weight.

Such EPM or EPDM rubbers are e.g. described in DE-OS 28 08 709.

Preferred polymers (C) are also selectively hydrogenated block copolymers of a vinylaromatic monomer (X) and a conjugated diene (Y) of the XY type. These block copolymers can be prepared by known processes. In general, for the preparation of the suitable XY block copolymers from styrene, _"" -methylstyrene, vinyltoluene etc. and from conjugated dienes such as butadiene, isoprene etc., the technology used for the production of styrene-diene block copolymers can be used, the in "Encyclopedia of Polymer Science and Technology", Vol. 15, Interscience, NY (1971) pages 508 ff. The selective hydrogenation can be carried out in ways known per se and means that the ethylenic double bonds are essentially completely hydrogenated, the aromatic double bonds remaining essentially unaffected. Such selectively hydrogenated block copolymers are described, for example, in DE-OS 30 00 282.

Preferred polymers (C) are e.g. polybutadienes grafted with styrene and / or acrylonitrile and / or (meth) acrylic acid alkyl esters, butadiene / styrene copolymers and poly- (meth) acrylic acid esters, e.g. also copolymers of styrene or alkylstyrene and conjugated dienes (impact-resistant polystyrene), i.e. Copolymers of the type described in DE-OS 16 94 173 (= US Pat. No. 3,564,077); preferred graft polymers (C) are e.g. also with acrylic or methacrylic acid esters or with vinyl acetate or with acrylonitrile or with styrene or with grafted polybutadienes, butadiene / styrene copolymers, butadiene / acrylonitrile copolymers, polyisobutenes or polyisoprenes, as described, for example, in DE-OS 23 48 377 (= US-PS 3 919 353) are described.

Particularly preferred polymers (C) are e.g. ABS polymers, e.g. in DE-OS 20 35 390 (= US-PS 3 644 574) or in DE-OS 22 48 242 (= GB-PS 1 409 275) are described.

• I. 10-40, vorzugsweise 10-35, insbesondere 15-25 Gew.-%, bezogen auf Pfropfprodukt, mindestens eines (Meth)-Acrylsäureesters und/oder eines Gemisches aus 10-35, vorzugsweise 20-35 Gew.-%, bezogen auf Gemisch, Acrylnitril und 65-90, vorzugsweise 65-80 Gew.-%, bezogen auf Gemisch, Styrol auf
• II. 60-90, vorzugsweise 65_-90, insbesondere 75-85 Gew.-%, bezogen auf Pfropfprodukt, eines Butadien-Polymerisats mit mindestens 70 Gew.-%, bezogen auf II, Butadienresten als Pfropfgrundlage erhältlich sind, wobei vorzugsweise der Gelanteil der Pfropfgrundlage II 70 % (in Toluol gemessen), der Pfropfgrad G 0,15 bis 0,55 und der mittlere Teilchendurchmesser d₅₀ des Pfropfpolymerisats (C) 0,2 bis 0,6, vorzugsweise 0,3 bis 0,5 µm betragen.

Particularly preferred polymers (C) are, for example, graft polymers which are obtained by grafting

• I. 10-40, preferably 10-35, in particular 15-25% by weight, based on the graft product, of at least one (meth) acrylic acid ester and / or a mixture of 10-35, preferably 20-35% by weight, based on the mixture, acrylonitrile and 65-90, preferably 65-80% by weight, based on the mixture, of styrene
• II 60-90, preferably 65 _-. 90, in particular 75-85 wt .-%, based on the graft product, of a butadiene polymer containing at least 70 wt .-%, based on II, of butadiene radicals as the graft base are available, preferably the gel fraction the graft base II is 70% (measured in toluene), the degree of graft G is 0.15 to 0.55 and the average particle diameter d _{50 of} the graft polymer (C) is 0.2 to 0.6, preferably 0.3 to 0.5 μm .

(Meth) acrylic acid esters I are esters of acrylic acid or methacrylic acid and monohydric alcohols with 1 to 8 carbon atoms.

In addition to butadiene residues, the graft base II can contain up to 30% by weight, based on II, residues of other ethylenically unsaturated monomers, such as e.g. Styrene, acrylonitrile, esters of acrylic or methacrylic acid with 1-4 C atoms in the alcohol component (such as methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate). The preferred graft base II consists of pure polybutadiene.

Since it is known that the graft monomers I do not graft completely onto the graft base II in the graft reaction, the graft polymers (C) to be used according to the invention contain, in addition to the actual grafted polymers, also homopolymers and, if appropriate, copolymers of the graft monomers I used for the grafting.

The degree of grafting G denotes the weight ratio of grafted graft monomers to the graft base and is dimensionless.

The average particle size d ₅₀ is the diameter above and below which 50% by weight of the particles lie. It can be determined by means of ultracentrifuge measurements (W. Scholtan, H. Lange, Kolloid. Z. and Z. Polymer 250 (1972), 782-796) or by means of electron microscopy and subsequent particle counting (G. Kämpf, H. Schuster, Angew Macromolecular Chemistry 14, (1970), 111-129) or by means of light scattering measurements.

• (a) 25-98 Gew.-%, bezogen auf Pfropfpolymerisat (C), Acrylatkautschuk mit einer Glasübergangstemperatur unter -20°C als Pfropfgrundlage und
• (b) 2-75 Gew.-%, bezogen auf Pfropfpolymerisat (C), mindestens eines polymerisierbaren, ethylenisch ungesättigten Monomeren, dessen bzw. deren in Abwesenheit von (a) entstandene Homo- bzw. entstandene Copolymerisate eine Glasübergangstemperatur über 25°C hätten, als Pfropf - monomere.

Particularly preferred polymers (C) are, for example, graft polymers

• (a) 25-98% by weight, based on the graft polymer (C), acrylate rubber with a glass transition temperature below -20 ° C. as the graft base and
• (b) 2-75% by weight, based on the graft polymer (C), of at least one polymerizable, ethylenically unsaturated monomer whose or whose homo- or copolymers formed in the absence of (a) would have a glass transition temperature above 25 ° C , as graft monomers.

The acrylate rubbers (a) of the polymers (C) are preferably polymers of acrylic acid alkyl esters, optionally with up to 40% by weight of other polymerizable ethylenically unsaturated monomers. If the acrylate rubbers used as the graft base (a) (as described on page 14 below) are in turn graft products with a diene rubber core, the diene rubber core is not included in the calculation of this percentage. The preferred polymerizable acrylic acid esters include C ₁ -C ₈ alkyl esters, for example methyl, ethyl, butyl, octyl and 2-ethylhexyl esters; Haloalkyl esters, preferably halogen C ₁ -C ₈ alkyl esters, such as chloroethyl acrylate and aromatic Esters such as benzyl acrylate and phenethyl acrylate. They can be used individually or in a mixture.

The acrylic rubbers (a) can be uncrosslinked or crosslinked, preferably partially crosslinked.

Monomers with more than one polymerizable double bond can be copolymerized for crosslinking. Preferred examples of crosslinking monomers are esters of unsaturated monocarboxylic acids with 3 to 8 carbon atoms and unsaturated monohydric alcohols with 3-12 carbon atoms or saturated polyols with 2-4 OH groups with 2-20 carbon atoms, such as, for example, ethylene glycol dimethacrylate or allyl methacrylate ; also polyunsaturated heterocyclic compounds, such as, for example, trivinyl and triallyl cyanurate and isocyanurate, tris _- acryloyl _- s-triazines, and also polyfunctional vinyl compounds, such as di- and trivinylbenzenes; but also triallyl phosphate and diallyl phthalate.

Preferred crosslinking monomers are allyl methacrylate, ethylene glycol dimethacrylate, diallyl phthalate and heterocyclic compounds which have at least three ethylenically unsaturated groups.

Particularly preferred crosslinking monomers are the cyclic monomers triallyl cyanurate, triallyl isocyanurate, trivinyl cyanurate, triacryloylhexahydro-s-triazine and triallylbenzenes.

The amount of crosslinking monomers is preferably 0.02 to 5% by weight, in particular 0.05 to 2% by weight, based on the graft base (a).

In the case of cyclic crosslinking monomers with at least three ethylenically unsaturated groups, it is advantageous to limit their amount to <1% by weight of the graft base (a).

Preferred "other" polymerizable ethylenically unsaturated monomers which, in addition to the acrylic acid esters can optionally be used to prepare the graft base (a), are, for example, acrylonitrile, styrene, α-methylstyrene, acrylamides, vinyl C ₁ -C ₆ -alkyl ethers. Preferred acrylate rubbers as the graft base (a) are emulsion polymers which have a gel content of ≥ 60% by weight,

The gel content of the graft base (a) is determined at 25 ° C. in dimethylformamide (M. Hoffmann, H. Krömer, R. Kuhn, Polymeranalytik I and II, Georg Thieme Verlag, Stuttgart 1977).

Acrylate rubbers as the graft base (a) can also be products which contain a crosslinked diene rubber from one or more conjugated dienes, such as polybutadiene, or a copolymer of a conjugated diene with an ethylenically unsaturated monomer, such as styrene and / or acrylonitrile, as the core.

The proportion of the polydiene core in the graft base (a) can be 0.1 to 80% by weight, preferably 10-50% by weight, based on (a). Shell and core can be independent of each other, uncrosslinked, partially crosslinked or highly crosslinked.

• 1. Acrylsäureesterpolymerisate und -copolymerisate ohne Dienkautschukkern und
• 2. Acrylsäureesterpolymerisate und -copolymerisate, die einen Dienkautschukkern enthalten.

Particularly preferred graft bases (a) for graft polymers (C) based on polyacrylic acid esters are summarized below:

• 1. Acrylic acid ester polymers and copolymers without diene rubber core and
• 2. Acrylic ester polymers and copolymers containing a diene rubber core.

The graft yield, i.e. the quotient of the amount of the grafted-on monomer (b) and the amount of the grafted-on monomer (b) used is generally 20 to 80% by weight. The determination can be carried out as described by M. Hoffmann, H. Krömer, R. Kuhn, Polymeranalytik, Vol. 1, Georg Thieme Verlag, Stuttgart 1977.

Preferred graft monomers (b) are 1-methylstyrene, styrene, acrylonitrile, methyl methacrylate or mixtures of these monomers. Preferred graft monomer mixtures are those of styrene and acrylonitrile in a weight ratio of 90:10 to 50:50.

Such graft polymers (C) on the basis of polyacrylic acid esters are, for example, in DE-AS 24 44 584 (= US-PS 4022748) and in DE-OS 27 26 256 (= _US - _PS 4,096,202) described.

Particularly advantageous graft polymers of this type are obtained if 2-20% by weight, preferably 2-15% by weight, based on (C), monomer (b) on 80-98, preferably 85-97% by weight. , based on (C), of the completely broken and slurried latex of (a) in the absence of suspending agent. The resulting powdered graft polymer can then be dried and homogenized in the desired ratio under the action of shear forces with the other components such that the average particle size d ₅₀ of (C) in the mixture according to the invention is 0.05 to 3 μm, preferably 0.1 to 2 µm, in particular 0.2 to 1 µm.

• Es muß darauf geachtet werden, daß die Pfropfmonomeren (b) in der wäßrigen Phase keine (stabile) Emulsion ergeben.

The term "in the absence of suspending agent" means the absence of substances which, depending on the type and amount, could suspend the graft monomers (b) in the aqueous phase. The definition does not exclude the presence of substances which, for example, have had a suspending effect in the preparation of a grafted graft base (a); in such cases the coagulant or precipitant used to break the latex (a) must be added in an amount which compensates for the suspending action of the substances used in the precursor; in other words:

• Care must be taken to ensure that the graft monomers (b) do not give a (stable) emulsion in the aqueous phase.

A graft polymer (C) prepared in this way in the absence of a suspending agent can be distributed as a constituent of the molding compositions according to the invention in the other resin components to an extraordinarily small particle size which, relatively unchanged, also survives longer processing times at a higher temperature.

The term "exceptionally low particle size" means that the number, shape and size of the graft polymer particles to be used essentially still match the number, shape and size of the graft polymer particles introduced into the melted other resin components even after homogenization.

As graft base (a) it is also possible to use those acrylate rubbers which are obtained as an aqueous emulsion (latex) and whose latex particles are 1-20% by weight, preferably 1-10% by weight, based on (a), already in an aqueous emulsion contain grafted monomers whose homo- or copolymers would have glass transition temperatures of 70 ° C.

Preferred such grafted monomers are alkyl acrylates, alkyl methacrylates, styrene, acrylonitrile, g-methyl styrene and / or vinyl acetate.

Such graft bases (a) are e.g. produced by emulsion polymerization or emulsion graft polymerization. However, they can also be prepared by preparing an acrylate rubber in solution or in bulk, then grafting on the graft monomers and then converting these rubbers into an aqueous emulsion which is suitable for further grafting processes.

Suitable graft bases (a) for acrylate rubbers of this particular embodiment are therefore, in addition to the polymers listed on page 12, preferably also graft polymers prepared in aqueous emulsion from acrylic acid ester polymers or copolymers, which may contain a diene rubber core, and ethylenically unsaturated polymerizable monomers.

The component (D)

worin "n" der Polymerisationsgrad ist, der zu einem Zahlenmittel des Molekulargewichtes (M ) zwischen 10 000 und 50 000 g/Mol korrespondiert.The thermoplastics based on polyetherimide to be used according to the invention are those with structural units of the formula (I)

where "n" is the degree of polymerization, which corresponds to a number average molecular weight (M) between 10,000 and 50,000 g / mol.

The thermoplastic polyetherimides are highly heat-resistant; they have a Vicat heat resistance of over 200 ° C, measured according to DIN 53 450.

In principle, the polyetherimides can be prepared by various processes with different intermediates. A common method is based on N-methylphthalimide. It is nitrated in the 3-position and reacted with the disodium salt of bisphenol A, the BPA (bis-N-methylphthalimide) ether being formed. This is condensed with m-phenylenediamine to give the high molecular weight polyetherimide. A monofunctional amine, e.g. Stearylamine, can also be used. Another synthetic process begins with the reaction of 3-nitrophthalic anhydride with m-phenylenediamine, followed by condensation with the disodium salt of bisphenol A. Here, monofunctional phenols are advantageously used as molecular weight regulators.

Further details are e.g. in U.S. Patent 38 38 097. An example of a polyetherimide is the commercially available "Ultem 1000 TM" from General Electric.

The state of the art

Components (A) to (D) are known as such.

Mixtures of polycarbonates and polyesters are also known (see for example DE-PS 1 187 793, DE-AS 1 694 124 and DE-OS 2 622 414.

Mixtures of polyesters and grafted polymers are also known (see, for example, US Pat. Nos. 3,919,353, 3,564,077, DE-OS 2,659,338 or US Pat. No. 4,096,202 or DE-OS 2,726,256).

Mixtures of polycarbonates and polymers are also known (see, for example, Japanese Patent Publication No. 18611/68 (Teijin, priority June 30, 1965), US Pat. No. 3,663,471, US Pat. No. 3,437,631, US Pat. No. 4,299,928 or DE- OS 3 114 494).

Mixtures of polycarbonates, polyesters and grafted polymers are also known (see for example US-PS 38 64 428 or DE-AS 23 43 609 or US-PS 42 64 487 or EP-OS 25 920 or US-PS 42 57 937 or EP-OS 20 605 or WO 80/00972 or DE-PS 15 69 448 or GB-PS 10 07 724.

Although molding compounds made from polycarbonates, polyesters and rubber-elastic polymers have many positive properties, they do not meet certain special requirements. In the event of prolonged exposure to temperature, for example when painting, tend to result Manufactured - especially thin - molded articles to warping.

Raising the heat resistance of such molding compositions to above 120 ° C is therefore an urgent technical need. However, the known good physical and chemical properties of polycarbonate / polyalkylene terephthalate mixtures are said to be largely retained.

From DE-OS 31 18 697 thermoplastic molding compositions based on polycarbonate, polyalkylene terephthalate and optionally one or more polymers are known whose warpage behavior is extraordinary due to the presence of small amounts of o, o, o ', o'-tetramethylbisphenol polycarbonate is positively influenced. However, these mixtures have the disadvantage that their toughness is significantly impaired by the presence of the o, o, o ', o'-tetramethylbisphenol polycarbonate.

The mixture according to the invention does not show this disadvantage.

The significant increase in the Vicat temperature of the mixture according to the invention, with the result of a significantly improved warping behavior, is surprising because the heat resistance to polycarbonate alone is raised only insignificantly by the addition of polyetherimide.

The molded articles produced from the molding compositions according to the invention do not warp due to the addition of polyetherimide, even at temperatures up to 130 ° C. As a result, the molded parts can be easily painted with suitable paint systems and used as gasoline-resistant, impact-resistant outer parts on motor vehicles, even at low temperatures.

The molding compositions according to the invention can be produced in conventional mixing units such as rollers, kneaders, single- and multi-screw extruders. It is expedient to premix the polycarbonate and the polyetherimide first and to add the remaining components only in a further operation.

• (A) 95 bis 50 Gew.-Teilen thermoplastischen, aromatischer Polycarbonate mit Gewichtsmittelmolekulargewichten M_w zwischen 10 000 und 200 000 (M _W ermittelt mittels Lichtstreuung),
• (B) 50 bis 5 Gew._-Teilen thermoplastischen Polyalkylenterephthalate, und gegebenenfalls
• (C) 0 bis 30, vorzugsweise 1 bis 20, insbesondere 3 bis 15 Gew.-Teilen eines kautschukelastischen Polymerisats mit einer Glasübergangstemperatur von unter -20°C, wobei die Summe der Gewichtsteile aus (A) + (B) + (C) jeweils 100 Gew.-Teile beträgt, und
• (D) 1 bis 20 Gew.-%, vorzugsweise 1 bis 16 Gew.-% und insbesondere 2 bis 10 Gew.-%, bezogen auf die Summe aus (A) + (D), eines Thermoplasten (D) auf Polyetherimidbasis, das dadurch gekennzeichnet ist, daß die Komponenten (A) und (D) in einem geeigneten Mischaggregat bei Temperaturen zwischen 290°C und 350°C homogenisiert und anschließend granuliert werden und man in einem weiteren Arbeitsgang bei Temperaturen zwischen 260°C und 290°C die Komponente (B) und gegebenenfalls die Komponente (C) zumischt.

The present invention thus also relates to a process for the production of molding compositions

• (A) 95 to 50 parts by weight of thermoplastic, aromatic polycarbonates with weight average molecular weights M _w between 10,000 and 200,000 ( M _W determined by means of light scattering),
• (B) 50 to 5 wt _-. Parts of thermoplastic polyalkylene terephthalates and, optionally,
• (C) 0 to 30, preferably 1 to 20, in particular 3 to 15 parts by weight of a rubber-elastic polymer having a glass transition temperature of below -20 ° C., the sum of the parts by weight consisting of (A) + (B) + (C) is 100 parts by weight, and
• (D) 1 to 20% by weight, preferably 1 to 16% by weight and in particular 2 to 10% by weight, based on the sum of (A) + (D), a thermoplastic (D) based on polyetherimide, which is characterized in that components (A) and (D) are homogenized in a suitable mixing unit at temperatures between 290 ° C and 350 ° C and then granulated and in a further operation at temperatures between 260 ° C and 290 ° C component (B) and optionally component (C) are admixed.

Another object of the invention are thermoplastic aromatic polycarbonates with weight average molecular weights M _w between 10,000 and 200,000 (M _w determined by means of light scattering), characterized in that they have 1 to 20 wt .-%, preferably 1 to 16 wt .-% and in particular 2 to 10 wt .-%, based on the sum of polycarbonate (A) and thermoplastic (D) of a thermoplastic (D) based on polyetherimide.

Another object of the invention is the use of these mixtures of polycarbonate (A) and thermoplastic (D) based on polyetherimide for the production of the molding compositions of (A) + (B) + (D) and optionally (C).

To increase the gasoline resistance, the molding compositions according to the invention can contain up to 5 parts by weight, based on the total weight of the components (A) + (B) + (C) + (D), of ethylene mono- or copolymers. In this sense, ethylene copolymers are polyethylenes, the residues of which, in addition to ethylene residues, consist of up to 30% by weight, based on ethylene copolymer, of residues of other copolymerizable monomers. Other copolymerizable monomers for the production of these ethylene copolymers are e.g. (Meth) acrylic acid and the monomers listed above for the preparation of graft base and graft for polymer (C).

The molding compositions according to the invention can contain the additives customary for polycarbonates and / or polyesters, such as lubricants and mold release agents, nucleating agents, stabilizers, fillers and reinforcing materials, flame retardants and / or dyes.

The filled or reinforced molding compositions can contain up to 30% by weight, based on the reinforced molding composition, of fillers and / or reinforcing materials. Preferred reinforcing materials are glass fibers. Preferred fillers, which can also have a reinforcing effect, are glass balls, mica, silicates, quartz, talc, titanium dioxide, wollastonite.

The polyester molding compounds equipped with flame retardants contain flame retardants in one Concentration of generally less than 30% by weight, based on the flame retardant molding compositions.

The flame retardants known for polycarbonates or polyesters or rubber-elastic polymers come into question, such as e.g. Polyhalodiphenyl, polyhalodiphenyl ether, polyhalophthalic acid and their derivatives and polyhalogen oligo- and polycarbonates, the corresponding bromine compounds being particularly effective. They also usually contain a synergist, e.g. Antimony trioxide.

The molding compositions according to the invention made of polycarbonates, polyalkylene terephthalates and thermoplastics based on polyetherimide and optionally rubber-elastic polymers and optionally the other additives mentioned can be processed into moldings such as bumpers, ramming strips or hub caps, so they are used, for example, in the exterior of automobiles.

Examples

• I. Polycarbonat hergestellt in bekannter Weise aus Bisphenol-A, Phenol und Phosgen, relative Viskosität 1,285, gemessen in Dichlormethan bei 25°C in 0,5 g pro 100 ml Lösungsmittel.
• II. Polyetherimid der Firma General Electric mit der Handelsbezeichnung "Ultem 1000 TM® Resin". Das Produkt hat die auf Seite 18 angegebene chemische Struktur. Das Zahlenmittel des Molekulargewichtes beträgt 19 200 (gemessen nach der Methode der Dampfdruckosmose). Die relative Lösungsviskosität beträgt 1,228 gemessen in Dichlormethan bei 25°C in Konzentration von 0,5 g pro 100 ml Lösungsmittel.
• III. Polybutylenterephthalat hergestellt in bekannter Weise aus Terephthalsäuredimethylester und Butandiol-1,4 mit einer Intrinsic-Viskosität von 1,18 dl/g, gemessen in Phenol/ o-Dichlorbenzol (Gew.-Verhältnis 1:1) bei 25°C im Ubbelohde-Viskosimeter.
• IV. Terpolymerisat hergestellt in bekannter Weise aus Ethylen, Acrylsäure und tert.-Butylacrylat im Gew.-Verhältnis 89:4:7 mit einem Schmelzindex von 6_-8 g/ 10 min. (gemessen bei 190°C und 2,16 kp Belastung nach DIN 53 735) und einer Dichte von 0,924 g/cm³ (gemessen nach DIN 53 479).
• V. Pfropfpolymerisat, 80 % Pfropfgrundlage aus vernetztem Polybutadien (Gelgehalt über 70 %, gemessen in Toluol) und 20 % Pfropfauflage aus 72 Teilen Styrol und 28 Teilen Acrylnitril, hergestellt in bekannter Weise.
• VI. Polycarbonat aus o,o,o',o'-Tetramethylbisphenol A, Phenol und Phosgen, relative Viskosität 1,29 in Dichlormethan bei 25°C in 0,5 g pro 100 ml Lösungsmittel.

Components used

• I. Polycarbonate prepared in a known manner from bisphenol-A, phenol and phosgene, relative viscosity 1.285, measured in dichloromethane at 25 ° C in 0.5 g per 100 ml of solvent.
• II. Polyetherimide from General Electric with the trade name "Ultem 1000 TM® Resin". The product has the chemical structure shown on page 18. The number average molecular weight is 19,200 (measured by the vapor pressure osmosis method). The relative solution viscosity is 1.228 measured in dichloromethane at 25 ° C in a concentration of 0.5 g per 100 ml solvent.
• III. Polybutylene terephthalate prepared in a known manner from dimethyl terephthalate and 1,4-butanediol with an intrinsic viscosity of 1.18 dl / g, measured in phenol / o-dichlorobenzene (weight ratio 1: 1) at 25 ° C. in an Ubbelohde viscometer .
• IV terpolymer produced in known manner from ethylene, acrylic acid and tert-butyl acrylate in the weight ratio 89: 4:. 7 having a melt index _6-8 g / 10 min. (measured at 190 ° C and 2.16 kp load according to DIN 53 735) and a density of 0.924 g / cm ³ (measured according to DIN 53 479).
• V. Graft polymer, 80% graft base made of cross-linked polybutadiene (gel content over 70%, measured in toluene) and 20% graft base made of 72 parts styrene and 28 parts acrylonitrile, prepared in a known manner.
• VI. Polycarbonate of o, o, o ', o'-tetramethylbisphenol A, phenol and phosgene, relative viscosity 1.29 in dichloromethane at 25 ° C in 0.5 g per 100 ml solvent.

Production of molding compounds

First, the polycarbonate and the polyetherimide are melted and homogenized in a twin-screw extruder under a nitrogen atmosphere at temperatures of 320 ° C. In a further, analog production step, the remaining components and the premix are then homogenized. The melt strand is degassed before it emerges from the nozzle, cooled in water, granulated and dried. Processing takes place on an injection molding machine.

Table I contains the results.

Claims (7)

1. Containing thermoplastic molding compositions (A) 95 to 50 parts by weight of thermoplastic, aromatic polycarbonates with weight average molecular weights Mw between 10,000 and 200,000 (Mw determined by means of light scattering) (B) 50 to 5 parts by weight of thermoplastic polyalkylene terephthalates and optionally (C) 0 to 30 parts by weight of a rubber-elastic polymer with a glass transition temperature of below -20 ° C, the sum of the parts by weight of (A) + (B) + (C) being 100 parts by weight that the polycarbonate component (A) contains 1 to 20% by weight, based on the sum of (A) + (D) of a thermoplastic (D) based on polyetherimide. 2. Molding compositions according to claim 1, characterized in that the polycarbonate component (A) contains 1 to 16 wt .-%, based on the sum of (A) + (D) of the thermoplastic (D) based on polyetherimide. 3. Molding compositions according to claim 1, characterized in that the polycarbonate component (A) contains 2 to 10 wt .-%, based on the sum of (A) + (D), of the thermoplastic (D) based on polyetherimide. 4. Molding compositions according to claim 1, consisting of components (A) + (B) + (D) and optionally (C), which are also ethylene homo- or copolymers, lubricants, mold release agents, nucleating agents, stabilizers, fillers, reinforcing materials, flame retardants or / and contain dyes. 5. A process for the preparation of the molding compositions of claims 1 to 4, characterized in that components (A) and (D) are homogenized in a suitable mixing unit at temperatures between 290 ° C and 350 ° C and then granulated and one in another Operation at temperatures between 260 ° C and 290 ° C component (B) and optionally component (C) and / or optionally ethylene homo- or copolymers, lubricants, mold release agents, nucleating agents, stabilizers, fillers, reinforcing materials, flame retardants or / and Dyes added. 6. Thermoplastic aromatic polycarbonates with weight average molecular weights Mw between 10,000 and 200,000 (Mw determined by means of light scattering), characterized in that they each have 1 to 20% by weight, based on the sum of polycarbonate (A) and thermoplastic (D) Contain thermoplastics (D) based on polyetherimide. 7. Use of the polycarbonates of claim 6 for the production of the molding compositions of claim 1.